[2.3.0] Grid column headers in wrong order when varying header group levels used

[2.3.0] Grid column headers in wrong order when varying header group levels used

After upgrading to GXT 2.3.0 the headings on our grids are out of order when some columns have header groups and others do not. It appears that all the headers with groups are being moved before the columns without headers groups.

A workaround we are doing for now is to add header groups to all the columns.